Although the U.S. Jewish vote tends to go Democratic in presidential elections, Republicans and Herbert Hoover were the first to reach out to Jewish voters and to push to save Holocaust victims, the author of a new book says.

“The relationship between Jews and the Republican Party goes back much longer than people realize and is much stronger than people realize,” author Rafael Medoff told Newsmax.TV.

And, he said, it’s possible the Jewish vote could swing to the GOP in November.

Watch the exclusive interview here.

“Jewish support for President Obama’s re-election has been dropping,” Medoff said in an interview on Thursday, which was Holocaust Remembrance Day.

He said the relationship between Republicans and American Jews goes back to the 1930s.

“By contrast, a number of leading Republicans, including former President Hoover, felt a genuine, heartfelt sympathy for the plight of the Jews who were being persecuted by the Nazis,” said Medoff.

“They wanted the U.S. government to take some action to rescue Jews before it was too late,” he said.

He said Hoover, who served as president from 1929-1933, was at the forefront of that effort and also played an instrumental role in the creation of Israel.

“Hoover was a Christian Zionist and he believed that the Jews had a biblical right to return to the biblical land of Israel,” said Medoff, head of the David Wyman Institute for Holocaust Studies. The Washington-based center focuses on the U,S. response to the Holocaust.

Medoff said Hoover, a Quaker, was above all a humanitarian.

“During World War I he had led relief missions in Europe that saved millions of people from starvation. He had a natural, almost instinctive, desire to help people who were downtrodden. When he heard about the persecution of Jews by the Nazis, he naturally wanted to help.”

In 1939, Hoover backed a congressional initiative to let 20,000 German Jewish children immigrate to the United States outside of the normal quota system, Medoff said.

It was a risky stance, since many in both political parties wanted to strictly limit immigration, and Hoover at that point still hoped to be the Republican presidential nominee in 1940. “It was not at all in his political self-interest,” Medoff said.

The bill was being vetted as Otto Frank, father of teenage diarist Anne Frank, was feverishly seeking permission to bring his family to the United States.

“Had that bill passed, it was possible that Anne Frank and her sister, Margot, could have been among the children admitted to the U.S.,” said Medoff.

Instead, the Frank family went into hiding and was ultimately betrayed to the Nazis. Anne and Margot died in the Bergen-Belsen concentration camp in March 1945.

Hoover kept fighting to help the Jews.

“Hoover in 1944 helped convince the Republican Party to adopt a plank in its platform calling for the rescue of the Jews and creation of a Jewish state,” Medoff said.

“That was the first time either major political party had made it part of their official platform to support Jewish statehood,” he said. “That put enormous pressure on the Truman administration” to back the creation of Israel.

Although American Jews tend to support the Democratic candidate in presidential rates, that is not always the case in mayoral, gubernatorial and congressional races, Medoff said. And while American Jews largely backed Barack Obama in 2008, his cool relations with Israel could alienate many Jewish voters this time around.

“In the Jewish community Republicans for a long time, suffered from a stereotype that they were really sympathetic to the little guy and they didn’t care much about Israel,” Medoff said. “Today of course, the Republican party is staunchly pro-Israel.”

Meanwhile, he said, “President Obama’s policies toward Israel clearly have veered away from the traditional pro-Israel position that American presidents usually take.”

Medoff said that in 1980, Jewish voters dropped support for Democratic incumbent Jimmy Carter and went over to Republican Ronald Reagan in droves.

“It’s entirely possible there could be a very significant Jewish shift to the Republicans in this presidential race,” he said, adding that could be crucial in swing states with a high number of electoral votes and substantial Jewish populations, like Ohio, Pennsylvania and Florida.